Nitroxyl (HNO) has been shown to have positive cardiovascular effects in in vitro and in vivo models of failing hearts. Due to its inherent reactivity, however, HNO must be generated in situ through the use of prodrugs. But beyond Angeli's salt (Na2N2O3), derivatives of Piloty's acid (RSO2NR′OR″), and acyloxy nitroso compounds (AcONOR2), very few physiologically useful HNO donors exist. To further elucidate and exploit the physiological effects of HNO, more classes of donor compounds need to be developed.